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作者：Miglioretti, DL; McCulloch, C; Zeger, SL
作者单位：Group Health Cooperative; General Electric; Johns Hopkins University
摘要：This article introduces a Bayesian hierarchical model for combining information across multiple images, Our work was motivated by an invasive functional brain mapping technique called direct cortical electrical interference that gives a sparse set of binary observations of an underlying ''true'' region at multiple sites on the brain surface. To model region shapes that may vary widely across individuals, we use mixtures of simple templates, for example, circles. These subject-specific template...
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作者：Arcones, MA; Kvam, PH; Samaniego, FJ
作者单位：State University of New York (SUNY) System; Binghamton University, SUNY; University System of Georgia; Georgia Institute of Technology; University of California System; University of California Davis
摘要：For any two random variables X and Y with distributions F and G defined on [0, infinity), X is said to stochastically precede I' if P(X less than or equal to Y) greater than or equal to 1/2. For independent X and 1, stochastic precedence (denoted by X less than or equal to(sp) Y) is equivalent to E[G(X-)] less than or equal to 1/2. The applicability of stochastic precedence in various statistical contexts, including reliability modeling, tests for distributional equality versus various alterna...
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作者：Hawkins, DM; Olive, DJ
作者单位：Southern Illinois University System; Southern Illinois University
摘要：Because high-breakdown estimators (HBEs) are impractical to compute exactly in large samples, approximate algorithms are used. The algorithm generally produces an estimator with a lower consistency rate and breakdown value than the exact theoretical estimator. This discrepancy grows with the sample size, with the implication that huge computations are needed for good approximations in large high-dimension samples, The workhorse for HBEs has been the ''elemental set,'' or ''basic resampling,'' ...
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作者：Qin, J; Leung, D; Shao, J
作者单位：Memorial Sloan Kettering Cancer Center; Singapore Management University; University of Wisconsin System; University of Wisconsin Madison
摘要：Nonresponse is a very common phenomenon in survey sampling, Nonignorable nonresponse-that is, a response mechanism that depends on the values of the variable having nonresponse-is the most difficult type of nonresponse to handle. This article studies a likelihood-based estimation method for data with nonignorable nonresponse. The likelihood is semiparametric in the sense that it consists of a parametric component for the response mechanism (such as a logistic model) and a nonparametric compone...
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作者：Scheaffer, RL
作者单位：State University System of Florida; University of Florida
摘要：In the information age of today, statistics is essential but statisticians are not. Yet statisticians have much to offer and must be proactive in their approaches to leaders in education, producers and users of data, the scientific community of scholars, and the public at large. Properly constructed bridges to these constituencies can convey the positive contributions of statistical thinking for all, strong academic programs in statistics, the value-added practice of statistics, and the infusi...
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作者：Scott, SL
作者单位：University of Southern California
摘要：Markov chain Monte Carlo (MCMC) sampling strategies can be used to simulate hidden Markov model (HMM) parameters from their posterior distribution given observed data, Some MCMC methods used in practice (for computing likelihood, conditional probabilities of hidden states, and the most likely sequence of states) can be improved by incorporating established recursive algorithms. The most important of these is a set of forward-backward recursions calculating conditional distributions of the hidd...
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作者：Eide, AL; Omre, H; Ursin, B
作者单位：Norwegian University of Science & Technology (NTNU); Norwegian University of Science & Technology (NTNU)
摘要：Offshore petroleum reservoirs are usually explored by acquisition of vast amounts of seismic reflection data and observations along a small number of wells drilled through the reservoirs. The seismic data a-re indirect measurements of reservoir characteristics and have good spatial coverage but low precision. The A ell observations are sparse but precise. Information from these sources of data are integrated to characterize the reservoir variables of interest-reservoir porosity in the current ...
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作者：Christensen, WF; Amemiya, Y
作者单位：Southern Methodist University; Iowa State University
摘要：Multivariate spatial or geo-referenced data arise naturally in such disciplines as ecology, agriculture, geology, and atmospheric sciences. In practice, interest often lies in modeling underlying structure and representing interrelationships in terms of a smaller number of variables. For such situations, statistical analysis using a latent variable model is proposed. We present a general model that incorporates spatial correlation and potential lagged or shifted dependencies and that can repre...
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作者：Dominici, F; Daniels, M; Zeger, SL; Samet, JM
作者单位：Johns Hopkins University; Johns Hopkins Bloomberg School of Public Health; Iowa State University; Johns Hopkins University
摘要：We analyzed a national data base of air pollution and mortality for the 88 largest U.S. cities for the period 1987-1994, to estimate relative rates of mortality associated with airborne particulate matter smaller than 10 microns (PM,,) and the form of the relationship between PM10 concentration and mortality. To estimate city-specific relative rates of mortality associated with PM,,, we built log-linear models that included nonparametric adjustments for weather variables and longer term trends...
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作者：Kibria, BMG; Sun, L; Zidek, JV; Le, ND
作者单位：State University System of Florida; Florida International University; University of British Columbia; British Columbia Cancer Agency
摘要：This article presents a multivariate spatial prediction methodology in a Bayesian framework, The method is especially suited for use in environmetrics, where vector-valued responses are observed at a small set of ambient monitoring stations ''(gauged sites)'' at successive time points. However, the stations may have varying start-up times so that the data have a ''staircase'' pattern (''monotone'' pattern in the terminology of Rubin and Shaffer). The lowest step corresponds to the newest stati...
